Slag runner on burners for protection against dripping slag

ABSTRACT

With a slag runner on burners or burner niches for protection against dripping slag, which occurs during the gasification of fine-particle fuels that contain ash, within a gasifier, reliable protection of the burner exits or the burner niches to prevent them from becoming clogged with slag is supposed to be made available. This is achieved in that the slag runner ( 8 ) is formed by a plurality of pipe elbows ( 9 ) through which cooling medium flows, which elbows, in the installed position, form a runner surface that faces into the interior of the gasifier, stands at a slant relative to the gasifier wall ( 1 ), and shields the burner ( 2 ) or the burner niche ( 7 ) at the upper region, in the direction of gravity, which surface configures an essentially acute angle (α) relative to the burner wall ( 1 ).

The invention is directed at a slag runner on burners or on burner niches for protection against dripping slag, which occurs during the gasification of fine-particle fuels that contain ash, within a gasifier.

In the gasification of such fuels, slag occurs on the, walls, and flows away in the direction of gravity, so that it can happen that the exit openings of the burners become clogged, at least in certain regions. Such slag occurs, for example, in the entrained gasification of fine-particle fuels that contain ash, for example in the case of fuels in the form of dust (<0.5 mm), for example coal, petroleum coke, biological waste, or biological fuels, or in the case of liquid atomized fuels such as oil, tar, refinery residues, or the like, whereby the gasification takes place with gasification media that contain oxygen, and under elevated pressure, at temperatures above the melting point.

For protection of a burner niche, DE 36 13 508 A1 discloses a pipe piece that projects out of the pipe wall, through which piece cooling water flows, and which piece forms an arch above the burner exit. In this connection, this pipe elbow is rammed with refractory materials, at least in part, but it is not entirely surrounded with ramming materials, so that overheating of this pipe bottom can occur. Also, a film of slag dripping down is merely shifted partway into the gasifier from the burner orifice, but not effectively and completely prevented.

A similar solution is shown by WO 2008/119753 A1, with the same disadvantages as described above.

Other disadvantages of the known solutions consist in that the oxygen that exits from the burner can be deflected in the wall direction, so that very hot flames (>2000° C.) can damage the wall they flow against. In addition, the flow of circulating water through the protective shield can lead to total failure of the system, particularly if the protective shield according to the state of the art is damaged in some way. Also, the known embodiment of slag diversion is particularly not very helpful if larger amounts of slag occur. No sharp tear-off edge for the slag is provided, nor is sufficient deflection provided.

This is where the invention takes its start, whose task consists in making available reliable protection of the burner exits or the burner niches to prevent them from becoming clogged with slag.

This task is accomplished, according to the invention, with a slag runner of the type indicated initially, in that the slag runner is formed by a plurality of pipe elbows through which cooling medium flows, which elbows, in the installed position, form a runner surface that faces into the interior of the gasifier, stands at a slant relative to the gasifier wall, and shields the burner or the burner niche at the upper region, in the direction of gravity, which surface configures an essentially acute angle relative to the burner wall.

With this embodiment, a cooled slag runner is made available, which ensures reliable deflection of the slag around the burner orifice even when larger amounts of slag occur.

Further embodiments of the invention are evident from the dependent claims.

According to the invention, it can be provided that the pipe elbows that form the slag runner are formed by a pipe piece whose inflow and outflow penetrates the gasifier wall and is connected with the latter in gas-tight manner.

With this construction, it is possible to provide the slag runner with its own cooling circuit, so that even very high temperatures are made possible, without any damage taking place. If damage occurs, the gasifier walls remain intact, for the remainder, and also, the slag runner can be installed and removed separately, without disturbing the rest of the construction.

The invention also provides that the pipe elbows that form the slag runner are formed by cooling pipe sections of the gasifier wall, which are bent out into the gasifier chamber, bent around, and bent back into the wall plane of the gasifier chamber, whereby it can also be provided that at least some of the pipe regions that form the slag runner are partly bent out behind the gasifier wall and bent back into the surface of the gasifier wall.

A practical different embodiment of the invention consists in that the pipe elbows that form the slag runner are formed by a part of the burner muffle, which is pushed into the interior of the gasifier by the corresponding amount. In this way, the region of the burner muffle pushed into the gas space directly forms the slag runner for slag that runs down the gasifier wall.

The invention also provides that the pipe elbows that form the slag runner are preferably configured to be pinned and rammed in refractory manner.

As was already mentioned initially, it can be practical to assign a separate coolant inflow and coolant outflow to the pipe elbows of the slag runner, as the invention also provides. A different embodiment consists in integrating the pipe elbows of the slag runner into the cooling circuit of the burner muffle, or, depending on the method of construction, integrating the pipe elbows of the slag runner into the cooling circuit of the gasifier.

Further characteristics, details, and advantages of the invention are evident from the following description and using the drawing. This shows, in

FIG. 1 a schematic section through a gasifier wall, with burner muffle and slag runner according to the invention,

FIG. 2 another embodiment of the slag runner, in a representation similar to that in FIG. 1,

FIG. 3 a top view approximately according to Arrow III in FIG. 1,

FIG. 4 a top view approximately according to Arrow IV in FIG. 3,

FIG. 5 another modified exemplary embodiment of the slag runner according to the invention, in a top view of a gasifier wall that is indicated, and

FIG. 6 a side view approximately according to Arrow VI in FIG. 5.

In a wall 1 of a gasifier, not shown in any detail here, an indicated burner 2 is provided within a burner muffle, designated in general with 3, whereby the burner wall 1 has cooling pipes 4 that are provided with a refractory ramming 5, whereby the burner muffle 3 is also provided with pipes 6 that serve for its cooling and can represent an integral part of the gasifier piping, if applicable.

The slag runner according to the invention, designated in general with 8, is positioned above the burner orifice designated with 7, in the direction of gravity; this slag runner is formed from cooling pipes 9, whereby here, as well, the cooling pipes 9 are surrounded by the refractory ramming 5.

In the example of FIG. 1, the slag runner 8 is positioned somewhat above the burner orifice 7, while in the example of FIG. 2, it lies directly within the alignment of the piping of the burner muffle 3. The inflow or outflow of cooling medium, in each instance, is designated with 10 in FIGS. 1 and 2, in each instance, whereby the flow passage of these elements through the burner wall 4 is structured in gas-tight manner, something that was not shown in any detail in the figure.

In FIG. 2, it is also indicated that of course, the pipes of the burner orifice 7 can also be rammed to be refractory, with ramming mass 5′. Also, the slag runner 8 can represent a part of the burner muffle, to the extent that the burner muffle is pushed into the combustion chamber of the gasifier by a corresponding amount, so that approximately the first three cooling pipe elbows form the front edge of the burner muffle, then directly form the slag runner.

As is evident from FIG. 3, in which not only the gasifier wall 1 but also the slag runner 8 are represented without refractory ramming, in the embodiment there, the slag runner 8 is formed by a single pipe coil of a pipe 9, through which a cooling medium flows. Not shown in any detail are the possibilities of providing the slag runner with its own cooling circuit or of coupling it with the piping of the burner muffle 3.

In FIGS. 5 and 6, another embodiment of the slag runner 8 is reproduced, specifically by means of formation of corresponding bends in the cooling pipes of the gasifier wall 1. In FIG. 5, in this connection, the individual pipes are numbered, in order to characterize their course, whereby here, the numbers 1 to 6 were chosen, which are not identical with the numbers of the preceding description, however, but rather merely refer to the cooling pipes of FIGS. 5 and 6.

It can be seen that the cooling pipe of the gasifier wall designated with 2 is passed all the way to the edge of the burner orifice 7; this location is designated with 2′ in FIG. 5. Then, the pipe 2 is angled away upward at an acute angle, and is then passed back over the orifice 7 in arch shape, whereby, as is evident from FIG. 5, the left pipe “2” forms a half-arch, while the pipe “2” that is on the right in the top view forms a half-arch to the right. Subsequently, the pipes “2” are bent back behind the gasifier wall 1, from there outward and downward, and then continue in the gasifier wall 1 again.

The gap that forms between the pipe elbows, designated with 2 a in FIG. 5, by means of the special bending of the pipe 2, is formed by a correspondingly bent cooling pipe of the gasifier wall that fills this gap and is designated with 3 in FIG. 5. The pipes that otherwise surround the burner orifice 7 are cropped back out of the gasifier wall, to the rear, in each instance, around the burner orifice 7, and back into the gasifier wall 1.

Of course, the exemplary embodiment of the invention described here can still be modified in many different respects without departing from the basic idea. For example, the invention is not restricted to a specific pipe elbow, also not to the number of pipe elbows that form the slag runner, and the like.

REFERENCE SYMBOL LIST

-   1 wall (gasifier) -   2 burner -   3 burner muffle -   4 cooling pipes -   5 refractory ramming -   6 pipes -   7 burner orifice -   8 slag runner -   9 cooling pipes slag runner -   10 coolant inflow/outflow 

1. Slag runner on burners or burner niches for protection against dripping slag, which occurs during the gasification of fine-particle fuels that contain ash, within a gasifier, wherein the slag runner (8) is formed by a plurality of pipe elbows (9) through which cooling medium flows, which elbows, in the installed position, form a runner surface that faces into the interior of the gasifier, stands at a slant relative to the gasifier wall (1), and shields the burner (2) or the burner niche (7) at the upper region, in the direction of gravity, which surface configures an essentially acute angle (α) relative to the burner wall (1).
 2. Slag runner according to claim 1, wherein the pipe elbows (9) that form the slag runner (8) are formed by a pipe piece whose inflow and outflow penetrates through the gasifier wall (1) and is connected with the latter in gas-tight manner.
 3. Slag runner according to claim 1, wherein the pipe elbows (9) that form the slag runner (8) are formed by cooling pipe sections of the gasifier wall (1), which are bent out into the gasifier chamber, bent around, and bent back into the wall plane of the gasifier chamber.
 4. Slag runner according to claim 3, wherein at least some of the pipe regions that form the slag runner (8) are partly bent out behind the gasifier wall (1) and bent back into the surface of the gasifier wall.
 5. Slag runner according to claim 1, wherein the pipe elbows (9) that form the slag runner (8) are formed by a part of the burner muffle, which is pushed into the interior of the gasifier by the corresponding amount.
 6. Slag runner according to claim 1, wherein the pipe elbows (9) that form the slag runner (8) are configured to be pinned and rammed in refractory manner.
 7. Slag runner according to claim 1, wherein the pipe elbows (9) of the slag runner (8) have a separate coolant inflow and coolant outflow assigned to them.
 8. Slag runner according to claim 1, wherein the pipe elbows (9) of the slag runner (8) are integrated into the cooling circuit of the burner muffle.
 9. Slag runner according to claim 1, wherein the pipe elbows (9) of the slag runner (8) are integrated into the cooling circuit of the gasifier. 